His temperature soared to 40C and his team, who were 50km into the wilderness sheltered only by 6ft snow walls, had to call for emergency help.

The treacherous conditions made a helicopter rescue impossible.

A second attempt failed when a skidoo crashed and two jeeps were defeated by the huge dumps of fresh snow that were smothering the glacier.

Mr Jansch, who was recording the trip for a documentary, said: "When the news of the aborted rescue reached us our hearts sank and we feared that Sean would have to spend another night in the tent without medication and with a rising fever."

But at 10pm the next night their satellite phone rang with good news.

Two "super jeeps" from the East Iceland Rescue Service were less than 6km away.

Mr Jansch added: "What followed was a roller-coaster ride, as the super jeeps crashed through all the fresh snow the glacier could muster, that ended at 3am."

Mr Rose, from St Neots, Cambs., recovered after two days on IV antibiotics in Nestaupstaður General Hospital.

Writing on Facebook from his hospital bed he said: "I felt proud to be a member of this team, things just happened, we looked out for each other, everyone had everyone else's back and they were there for me when I needed them most.

"We succeeded in so many ways to get to where we did but failed to reach our final destination. That doesn't sit well with me, so Mr Vatnajökull we have unfinished business."

Mr Rose and Mr Jansch flew back to the UK on Wednesday(16/4) morning.

Mr Jansch added: "We know that we are up to this challenge, and more, and we're determined to come back to finish what we started."

Mr Rose won Britain's first gold medal in a World Cup race and became a world champion water skier.